Typically, when a video frame is numbered, some number of characters (e.g., numbers) are visually displayed within the video frame. In system 100 of FIG. 1, a typical arrangement is illustrated: set top box 120 receives an encoded signal from signal source 110. Set top box 120 decodes the encoded signal into a format appropriate to be output to television 130 (or some other form of display device) for display. When the video frame is displayed by the television, the frame number is visible at the same time as the rest of the video frame. For a human viewer, this may provide a relatively simple way to identify the frame number of a particular frame when a video frame is displayed for a sufficient period of time (e.g., a half second or more).
However, if the video frame is output to a computerized device, reading a character-based frame number from the video frame may involve the use of optical character recognition (OCR). OCR may be processor-intensive, especially if frame numbers are to be determined in real time for a significant number of video frames.